Division - Unknown Factors
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LearningTranscript
00:00Hey kids, I am just going through the unknown factor reef in the division ocean.
00:10Oh the shark?
00:11Yeah, you don't need to worry about him.
00:13He is my friend and we are looking for the unknown factor treasure.
00:17In order to find the treasure we need to learn some division with unknown factors.
00:20Will you guys help me?
00:23Great, let's go!
00:27To start off, let's solve a division problem in one way and then look at its factors.
00:36The problem to solve is 15 divided by 3 equals blank.
00:41One way to solve this is by starting with a drawing.
00:45We are dividing by 3 so we have 3 boxes.
00:51The problem is telling us we will take 15 circles and divide them equally among 3 groups.
00:56We will put a circle in each group until all circles are gone.
01:04We divided the 15 circles into 3 groups like the problem shows.
01:08Can you tell me how many circles are in each box?
01:13There are 5 circles!
01:15Great job!
01:1615 divided by 3 equals 5.
01:19Did you know that in every division problem there is also a multiplication problem?
01:24We had 3 groups of 5 and 3 times 5 equals 15.
01:29In the division problem up top the 15 we are dividing by is the product in the multiplication
01:34problem.
01:36Now this may not seem like a big deal but if we recognize that a division problem can
01:40be figured out by using multiplication it can make things so much easier.
01:46We are going to look at the factor family also called a factor tree.
01:52The 15 here is made up of the factors 5 and 3.
01:575 multiplied by 3 equals 15.
02:033 multiplied by 5 equals 15 as well.
02:10You probably already know all this so let's see how division works with this factor family.
02:16Starting at the top 15 divided by 3 equals what?
02:225.
02:24Great job!
02:25We can also say that 15 divided by 5 equals 3.
02:32By using our fact families we basically know that we can figure out an unknown number in
02:36division by using our multiplication strategies.
02:40This is awesome!
02:41Let's try a new type of problem and see how we do.
02:46This problem says 28 divided by 7 is equal to 7 multiplied by blank.
02:52In order to solve problems like this we can learn how to turn division problems into multiplication
02:56problems.
02:58Let's start with writing down just the first part of the problem.
03:02Now that we have the division problem let's write down what the multiplication problem
03:06would be.
03:09We know that the first number in the division problem is the product in a multiplication
03:13equation so let's put down an equal sign and 28 as the product.
03:19They gave us one of the factors which is 7 so we can put 7 in the equation.
03:25We just turned the division problem into a multiplication problem.
03:28Now we have 7 times something equals 28.
03:32Because we know the product is 28 and one factor is 7 we can now count by 7 until we
03:37get to 28.
03:39If you want to count with me hold up your fingers each time we count by 7.
03:43We count 7, 14, 21, 28.
03:49How many fingers are you holding up?
03:52The answer is 4.
03:5328 divided by 7 is 4 and 7 multiplied by 4 is 28.
03:59Great job!
04:02So the answer to the question at the top is 28 divided by 7 is equal to 7 times 4.
04:08I think you are getting the hang of this.
04:10Let's do one more problem to find that treasure.
04:14The problem says 30 divided by 6 is equal to 6 times blank.
04:20To find the answer just like the last one go ahead and try to write the division and
04:24multiplication problem.
04:28We have 30 divided by 6 equals blank for our division equation.
04:32We have 6 multiplied by blank equals 30.
04:36We knew that 30 was the product and 6 was one of the factors.
04:41Because 6 is one of the factors we can count by 6.
04:45Count by 6 with me.
04:466, 12, 18, 24, 30.
04:51How many times did we count?
04:54We counted 5 times!
04:56Great job!
04:5730 divided by 6 is equal to 6 times 5.
05:01We did it!
05:05Yes!
05:06We found the treasure.
05:08Let's open it and see what's inside.
05:12Oh man, just a division symbol and an octopus.
05:16Well, it was still fun.
05:19Thanks for joining me.
05:20I am going to keep exploring.
05:21Goodbye!